Today, automobile internal combustion engines are a principal source of air pollution. During the combustion process various pollutants are formed and released into the atmosphere. These pollutants include unburned hydrocarbons, carbon monoxide, and various oxides of nitrogen. Though these pollutants are eminated principally from combustion chambers a very substantial amount also arise from crankcase vapor emissions. These pollutants arise from "blow-by" gases which escape past the piston rings in the engine cylinders during the power stroke. When the mixture of fuel and air in each cylinder is ignited the gases and gas borne particulates formed in the cylinders are blown past the rings and into the crankcase.
To minimize the pollution created by crankcase gas emissions a system of positive crankcase ventilation has been developed. With this system the blow-by gases from a crankcase are routed back into the engine combustion chambers through the engine intake manifold. Such systems include a PCV valve which serves to adjust the flow of crankcase blow-by gases to the flow of the air-fuel mixture developed in the carburator and also to prevent the air-fuel mixture from being drawn into the crankcase itself. Although this system does remove a substantial portion of the pollutants which otherwise would be admitted to the atmosphere from the crankcase it has failed to eliminate completely such emissions due to the fact that the recycled pollutants from the crankcase are not totally burned in the engine combustion chambers in which case they are passed to the atmosphere through the exhaust manifold. To minimize this problem positive crankcase ventilation systems have been provided with filtering means and with heating means for heating the vapors from the crankcase prior to entry into the engine intake manifold as disclosed in U.S. Pat. No. 3,779,221. These improved systems however have not proved efficient nor really effective in achieving substantial reductions in crankcase emissions of pollutants into the atmosphere.
Accordingly, it is a general object of the present invention to provide an improved method for controlling pollution emissions of internal combustion engines and to provide means for practising this method.
More specifically, it is an object of the present invention to provide a pollution control device for effecting a substantial reduction in atmospheric pollution resulting from pollutants eminating from internal combustion engine crankcases.
Another object of the invention is to provide a pollution control device for an internal combustion engine of relatively simple and economic construction and with one which may be installed and serviced with facility.
Yet another object of the invention is to provide a pollution control device for an internal combustion engine which may not degrade but actually enhance mileage efficiency.